Galvanizing machine



Nov. 14, 1933. J,W. FREE GALVANIZING MACHINE 6 Sheets-Sheet l Filed Sept 20 INVENTOR WK Wk ,6 i'4 gm I M NOV. 14, 1933. I J w E 1,935,087

GALVANIZING MACHINE I Filed Sept. 20, 1930 6 Sheets-Sheet .2

NOV. 14, w E GALVANIZING MACHINE Filed Sept. 20, 1930 6 Sheets-Sheet 4 Nov. 14, 1933; J, w, FREE GALVANIZING MACHINE Filed Sept. 20, 1930 6 Sheets-Sheet 5 NOV. 14, 1933- J. w FREE 1,935,087

GALVANI Z I-NG MACHINE Filed Sept. 20. 1950 e Sheets-Sheet e INVENTOR MJM Patented Nov. 14, 1933 UNITED STATES.

1,935,087 GALVANIZI'NG monnvn John W. Free, Aliquippa, Pa.,

and Laughlin Steel Corporation,

assignor to Jones Pittsburgh,

2a., a corporation of Pennsylvania Application September 20, 1930 Serial No. 483,273

10 Claims.

My invention relates to an apparatus for applying a protective coating to metallic articles such as pipe lengths. In particular, the invention deals with improved means for passing articles to be coated through a suitable galvanizing bath and removing them therefrom.

This application is a continuation in part of my application filed September 19, 1929, Serial No. 393,615.

It has been the practice heretofore in galvanizing pipe, to transfer a lift or batch of pipes from the pickling and washing baths to a suitable rack adjacent a tank of molten spelter. From the racks the pipes are pushed into the'spelter by a workman, a shield being provided longitudinally of the tank to prevent the spelter from splashin'g out the other side of the tank where workmen stand ready to receive and withdraw the pipe from the bath. After the pipes have been dumped into the bath, it is necessary to force them downward therein, since, because of the steam resulting from the water adhering to the pipes, they show a tendency to float. After. the pipes have been forcibly submerged for the required length of time, workmen at the front of the tank pull the pipes forward under the shield and lift them from the tank.

This practice is objectionable from several standpoints. In the first place, the thickness of the galvanizing applied to the pipes is not uniform because some of the pipes are immersed for a longer period than others. Another objection is that the tendency of the pipes to float, because of the steam generated therein, requires that they be forcibly maintained below the level of the spelter bath. The interior of the pipes, furthermore, issometimes not fully coated, bare spots being left without any galvanizing thereon. Further objections are that the process requires a numberof workmen and is difficult and inconvenient to carry out.

According to the present invention, I have provided means for positively feeding pipe individually into and through a galvanizing bath. I also provide means for automatically raising the pipe from the bath to a position such that it can be readily removed therefrom. My invention also contemplates amethod of introducing pipes into the spelter bath at an angle to the horizontal, so that one end leads the other. In this way, the flux and spelter rise through the pipe gradually, so that a thorough coating of the-interior is insured, as contrasted to the possible failure to coat thoroughly the inside of the pipe by lowering 55 the latter in the spelter in the horizontal position.

According to one form of the invention, 1 provide a horizontal screw conveyor to which pipe lengths are adapted to be delivered from a receiving rack. The horizontal screw conveyors ad .vance the pipe toward the galvanizing tank. 30 Inclined screw conveyors projecting into the bath receive pipe from the horizontal conveyors and forcibiy submerge it in the bath, wherein it is supportedon suitably shaped slides as it descends through the bath. The two sets of conveying screws are arranged so that the transfer of pipe from one to the other is positively effected without possibility of skipping or interference. A vertically reciprocable lifter rod is automatically separated for raising one end of the pipes from the bottom of the bath to the top thereof. From this position, the pipes can readily be seized with tongs, by a workman and withdrawn from the tank through a scraping die, and delivered to the cooling beds.

The preferred form of my invention comprises similar horizontal and inclined screw conveyors, but also is provided with means for placing the pipes on the screws at an angle, so that they are dipped into the bath with one end leading the other. In this form of the invention, I preferably provide lifting means in the form of a screw conveyor for lifting the ends of the pipes which were first introduced into the bath up to the surface thereof to permit them to be removed. The pipes slide down guides into the bath as in the first form of the invention, and I provide an extra flight on one of the lowering conveyors to insure that the pipes are transferred to the .raising conveyor. In order to assist this transfer, the last flight of the raising conveyor is made 'wider than the other flights thereof. As the ends of the pipes are raised, they are shifted to a holding rack and are then removed from the bath by a workman with tongs and pulled through the scraping die. 7 After passing through the die, the trailing ends of the pipes are shifted to a drip pan, so that spelter flowing from within the bath will be returned to the pan. The drip pan may preferably be heated to prevent the spelter from freezing thereon. After the pipes have been gripped by the tongs, the tongs are preferably hooked into a continuous chain conveyor, which completes the removal of the pipe from the bath. After the pipes have been withdrawn from the tank, they are delivered to a cooling bed.

The invention also contemplates means for agitating the flux on the spelter to insure thorough coatingof the pipe therewith. 110

For a complete understanding of the invention, reference is made to the accompanying drawings illustrating a present preferred embodiment thereof.

In the drawings,

Figure 1 is a side elevation of the invention with the container for the coating bath being shown in section;

Figure 2 is a plan view;

Figure 3 is a sectional view to an enlarged scale along the line III-III of Figure 2;

Figures 4a and 4b together represent a plan view of a preferred form of the invention;

Figures 5a and 5b together represent, a side elevation thereof;

Figures 6a and 6b together constitute a section taken along the line VI-VI of Figure 4a, showing a detail which is omitted from the plan and elevational views, for the sake of clearness; and

Figure '7 is an isolated detailed view of one of the inclined lowering conveyors and the lifting conveyor cooperating therewith.

Referring in detail to the drawings, and especially to Figures 1-3, a galvanizing tank 10 contains a bath of molten zinc. A receiving rack 11 is located adjacent the bath and supports the pipe to be coated in convenient relation to the feeding mechanism. In order to advance the pipe from the table 11 to the bath 10, I provide a conveyor 12 consisting of screws 13 and rails 14. Runways 11a connect the rack 11 and the conveyor 12. The screws 13 of the conveyor 12 are mounted with their axes horizontal and serve to transfer pipe from the table 11 to a second conveyor 15 having screws 16. The screws 16 are journalled in bearings 17 so that the axes of the screws are inclined to the vertical. The bearings 17 are carried by a bearing bracket 18 supported on a transverse beam 19 which extends over the galvanizing tank 10. The beam 19 is supported at its ends by the columns 20 and 21.

A motor 22 is mounted on the beam 19 near one end thereof. Through a chain and sprocket connection, the motor 22 drives a shaft 23 and a shaft 24. The shaft 23 is connected by bevel gears to the screws 16 while the shaft 24 is similarly connected to the screws 13. The connection between the motor and the shafts is such that the screws of the conveyors are driven at the same speed.

The motor is preferably of the variable speed type so that the rate at which pipe passes through the bath may be varied.

A lifter rod 25 is reciprocably mounted in a bearing 26 extending from the beam 19. An operating lever 27 for the lifter rod is pivoted in a bearing bracket 28 which also provides a support for a gear 29 and a cam 30 fixed to a common shaft 31. The gear 29 is driven by a pinion 32 keyed to the shaft 23. The lever 27 has a cam roller 34 thereon engaging the cam 30 so that as the'latter is rotated, the lever 27 oscillates about its bearing and reciprocates the rod 25. The rod 25 is swiveled to the lever 2'7 at 35 and has an offset on 36 near the lower end thereof for engagement with the pipe in the bath 10.

A cam 37 has inclined surfaces for engaging pins 38 in collars 39 on the rod 25. As the rod is lowered, the upper pin 38 causes the arm 36 to be turned at right angles to the length of the tank 10. When the rod is lifted, the lower pin 38 causes the arm 36 to be turned parallel to the tank.

The galvanizing tank 10 is provided with guide rails 46 and with scraper jawo 41.

In operation, pipe lengths are fed by a workman behind the tank from the receiving rack 11 to the horizontal conveyor 12, and thence to the inclined conveyor 15. The inclined conveyor, cooperating with the guide rails 19, rolls the pipe lengths into the galvanizing bath in a horizontal position. The feed effected by the conveyor is positive so that any tendency for the pipe to float is overcome and the latter are given a uniform coating of the galvanizing. As pipes pass down the rails 40 they are discharged from the conveyor and come to rest on the foot of the rails.

The lifter rod 25 reciprocates continuously as long as the conveyors are in operation and may be so adjusted that it reaches the bottom of its stroke as a pipe length is discharged from the conveyor 15. When in its lower position, the rod is turned by the engagement with the upper pin 38 with the cam 37 so that it is in position to engage the pipe resting on the foot of the rails 40 when lifted. Continued operation of the machine causes one end of the pipe resting on the rails 40 to be lifted by the arm 36 to a point adjacent the jaws of the scraper 41 as best shown in Figure 1. At this instant, the jaws 41 are opened, the coated pipe is inserted therein and the jaws are then closed while the pipe is drawn therethrough. Further upward movement of the lifter rod 25 turns the arm 36 through an angle of 90 as a result of the engagement of the lower pin 38 with the cam 37.- .The rod 25 is then in position to pass downwardly toward its lower position without being interfered with by any pipe lengths that have been discharged from the conveyor 15, since the last lifting operation. As the rod 25 nears its lower limit of movement, the foregoing cycle of operations is repeated.

A preferred form of the invention is illustrated in Figures 4a through '7. In these figures, elements corresponding to those already shown in Figures 1 through 3 are indicated by the same reference numerals. The driving motor and its connections to the system are omitted but are the same as in the form first described. One difference between the first form of the invention and that under discussion is that the runways lla connecting the rails of the rack 11 to the conveyor 12 are not of the same length but increase in length from left to right, as shown in Figure 4a. Thus, when the pipes are fed forward from the position on the rack 11 indicated at 50 in Figure 4a toward the conveyor 12, the right hand ends of the pipes are given a lead over ,the left hand ends thereof, as indicated at 51.

The screws 13 of the conveyor 12 and-the screws 16 of the conveyor 15 operate to lower the pipe lengths into the bath with the right hand end ahead of the left hand end. By reason of the inclined position of the pipes as they pass through the bath, there is a gradual rise of flux and spelter through the pipe, so that the interior thereof is thoroughly coated. The coating of the inside and outside walls of the pipes continues as it is lowered through the bath on the guide rails 40.

In the preferred form of the invention, the means for raising the coated pipes from the bottom position on the guide rails 40comprises a lifting screw 52 located adjacent the right hand lowering screw 16. The screw 52 is journalled in bearings 53 supported on an arm 54 extending from the beam 19.

' the screw 16.

The screw 52 is driven by a sprocket 55 on the shaft 23 and a chain 56 which engages a sprocket 57 on a shaft 58. The shaft 58 is rotatably carried at the end of the arm 54 and is connected to the screw 52 by bevel gears 59. The lower run of the chain 56 passes through suitable openings in the webs of the beam 19 and over an idler sprocket 60. A notched plate 61 depends from the arm 54 and serves as a guide and receiving rack for the pipe being raised by the screw 52. The guide 61'prevents the pipe from falling off the flights of the screw 52 and the notch in the guide serves as a receiving shelf for the pipe when they have been raised to the proper level. The top flight of the screw 52 is disposed at an angle so that the pipe will be slid onto the shelf of the guide 61 at the proper time.

As previously stated in the description of the first form of the invention, the horizontal screws 13 and the inclined screws 16 are properly timed relative to each other, so that pipe discharged by the screws 13 will be positively engaged by the flights of the screws 16 and thus rolled into the bath. It is easy to attain this cooperation of the horizontal and inclined screws, since the pipe tends naturally to roll downgrade. When the pipe are transferred from the inclined screw 16 to the lifting screw 52, a different problem is met. The pipe tend to fall to the bottom of the guide rail 40 and special provisions are necessary to insure their being seized by the lowest flight of the lifting screw 52. Such means take the form of an additional flight 62 secured to the lowest flight of the screw 16, as shown in Figure '7 and extending in an opposite direction. The lowest flight of the lifting conveyor 52 is widened as at 63 to cooperate with the additional flight'62 on By properly positioning these flights relative to each other, as shown in Figure 7, the flight 62 will force the pipes onto the wide portion of the flight 63 after they have been released by the movement of the screw 16. The screws 16 and 52 are also adjusted so that there will be no interference between the flight 62 and the wide flight 63. The pipes are thus forced positively into the proper position on the lifting screw 52 and after they have been started, they are maintained thereon by the lower end of the guide 61 until they pass the notch therein, whereon they are finally deposited.

The descending pipes are thus engaged at one end by the lifting screw 52 and are successively raised to a position shown at 64 in Figure 5a, in

- which their leading ends protrude from the tank and can thus be seized readily with tongs 65. When the pipe have been gripped by the tongs, the tongs are hooked into a chain conveyor 66 which draws the pipes through the scraping die 41. After the ends of the pipe have passed the die, the workman pushes them over into the drip pan 67, where spelterdripping from the ends of the pipe is collected and returned .to the bath. When the pipes have been raised clear of the drip can 67, they are discharged to the cooling bed As the right hand ends of the pipe are raised arm 69. The arm 69 serves to prevent the left hand ends of the pipes from floating upwardly as the right hand ends thereof are raised.

A shield 70 is illustrated in Figure 6a. This shield extends lengthwise of the tank 10 and is supported in any convenient manner, for example, from the beam 19. The shield prevents the spelter from splashing on the workmen at the front of the tank as the pipes are fed into the bath. The shield is omitted from the other figures to avoid concealment of vital features.

In order to insure thorough fluxing of the pipes as they are passed into the bath, I have found it desirable to provide means forcirculating the flux floating on the spelter behind the shield "70. As an example of such means, I have shown a paddle-wheel '71 carried at the end of a shaft 72 journalled in bearings '73 supported from the beam 19. The shaft 72 is driven by a chain and sprocket drive from the shaft 23 through bevel gears 74. The paddle-wheel '71 is effective to cause the desired circulation of the flux on top of the spelter bath, to prevent the screw 16 or the pipe delivered thereby from cutting a clear path through the flux so that the pipes are not thoroughly covered therewith. By circulating the flux, fresh fluxing material is supplied to the descending pipe continuously and the coating thereof with the fluxing material is made much more thorough and complete.

It will be apparent from the foregoing description that the invention described herein represents a' marked improvement over the previous method and apparatus for galvanizing pipe. Manual handling of thepipe is largely dispensed with. The process is always under easy and effective control. The required period of immersion for difierent sizes and different thicknesses of coatings can be obtained by varying the speed of the motor driving the feeding mechanism. Small'pipes can be fed two at a time and large pipes individually. The interior of the pipe is effectively coated as well as the exterior, and the pipes are passed continuously through the bath, so that there can be no jamming of the mechanism or collection of pipes at any point in their travel.

The transfer of pipes from one conveyor to the next is effected positively without any chance of interference between adjacent conveyors. The tendency of the pipes to float is overcome by a positive, continuous, downward feeding mechanism and a retaining arm 69 for preventing floating of the free ends of the pipes. By lowering one end of the pipes into the bath first, and then raising the same end out of the bath first, intimate contact of the spelter with all parts of the interior of the pipes is effected. 130

Although I have described and illustrated but a single preferred embodiment and application of the invention, it is not to be limited to the specific details of the structure illustrated or the use described, since it may be otherwise embodied 135 and utilized. Any changes falling within the scope of the invention may, therefore, be made without departing from the spirit of the appended claims.

I claim: 14;

1. In a galvanizing machine, a receiving rack for supporting the articles to be coated, a hori zontal screw for feeding them to a galvanizing bath, an inclined screw for passing them through the bath, a reciprocable arm for lifting the arti- 14E cles from the bath and a common driving means for said screws and said lifting arm.

2. A galvanizing machine comprising a galvanizing bath, a beam sup ported'thereover, a receiving table adjacent the bath, a screw for ad= 156 vancing articles to be coated from said table, a second screw for dipping them in the bath, a lifting screw for raising them therefrom, and a com mon driving means for said screws mounted on said beam.

3. The combination with a galvanizing tank, of screw conveyors for feeding metal lengths thereinto one end ahead of the other, a screw conveyor for raising the leading end and a rack for receiving and holding said uplifted end.

4. In a pipe feeding mechanism for galvanizing, a lowering screw and a guide rail, a raising screw, and a reversed flight on the lowering screw for positively transferring pipe from the lowering screw to the raising screw.

5. In a pipe feeding mechanism for galvanizing, a lowering screw and a guide rail, a raising screw, a reversed flight on the lowering screw for positively transferring pipe from the lowering screw to the raising screw, and a widened flight on the raising screw for receiving pipe from the lowering screw.

6. In a coating machine, a rack supporting a supply of articles to be coated, a coating bath, screw conveyors for advancing articles laterally to the bath at an angle thereto, screw conveyors for lowering the articles into the bath one end ahead of the other, a screw conveyor for raising the leading ends of the articles from the bath,

and means on the lowering conveyor for transferring articles therefrom to the raising conveyor.

7. In a coating machine, a bath, a screw conveyor therein for 'raising articles from the bath, a support for articles raised from the bath, said conveyor having a distorted flight for positively transferring articles from the conveyor to the support.

8. In a pipe feeding mechanism for galvanizing, a lowering screw and a guide rail, a raising screw, and means on the lowering screw for positively transferring pipe from the lowering screw to the raising screw.

9. In a pipe feeding mechanism for galvanizing, a lowering screw and a guide rail, a raising screw, means on the lowering screw for positively transferring pipe from the lowering screw to the raising screw, and means on the raising screw for receiving pipe from the lowering screw.

10. In a coating machine, a supporting rack for articles to be coated, a coating bath, a screw conveyor for receiving articles from the rack and moving them toward the bath with one end in advance of the other, a screw conveyor for lowering articles into the bath in similar position, and a screw conveyor for raising the leading ends of the articles from the bath.

JOHN W. FREE. 

